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JEROME sTocEiNe AND EDWARD P. SEAEEER, 0E ROCHESTER, NEW YORK.

Letter-s .Patent No. 76,545, dated April 7, 1868.

IMPROVEMENT 1N STEAM-ENGINE SLIDE-VALVES.

TO ALL WHOM IT MAY CONCERN':

Be it known that We, JEROME STOCKING and' EDWARD P. SHAFFER, ofRochester, in the county of Monroe,

and State of New York, have invented certain new and useful Improvementsin Slide-Valves for Steam- Engines; and we do herebyl declare that thefollowing is a full, clear, and exact description thereof, referencebeing had tothe accompanying drawings, making part of thisspecification, in which- Figure 1 is a vertical section of ourinvention, taken in the direction of the red line Vo in lig. 2.

Figure 2 is a horizontal sectional View, taken in the plane of the redline n in iig. 1.

Like letters indicate corresponding parts in both figures.

This invention will be better 'understoodby reference to' the drawingsand specification.

We provide each valve proper with two sets of ports, and B', for thelive, aud two, G, for the exhaust steam. The base-plate of thesteam-chest is provided with two elevated port-chambers, D, the adjacentsides of which are cast and planed. exactly parallel to each other.These faces constitute the valve-seats, each valve having two seats, andthe steam-ports b, 02,' andf, are cut through them.

The valve is composed of two cut-off plates, E and F, constructed .lasshown in 'the drawings. They are -connected together by means of twoadjusting-screws, G, the heads' of which are made with a sphericalshoulder, as shown at t, g, 1. The plate F is cast with recesses, r, inthe inside, to receive the screw-heads 7L, and theo-pposite or outsideis slightly recessed, to receive the spherical face of the set-nuts g.The screws are tapped through the opposite plate, E, as shown. By makingthe valve or cut-olf plates sepa-rate, and connecting them byset-screws, they may be perfectly adjusted to t the space between thetwoelevatedseat or portchambers D. The spread of the valve is'iset orregulated by inserting the screws Gr in the plate F, and turning thenuts g firmly against it. The screws are then'turned into the oppositeplate, E, until the valve will just move freely between the seats, andthe set or jam-nuts y are turned firmly against the plate E, after whichthe nuts g are turned back slightly, so as to leave the plate F looseupon the screws, and yet the spreadof the plates is rigidly-limited. Thenuts g are fixed in this adjustment by the pins z'.

It will be seen that by this means the valpe may be `spread at any time,so' as to compensate for any wear that might, by any possibility, occurbetween the valve and seats, and the plates E and F are held rigidlyfrom being spread or separated, by the pressureof-the steam against theseats, and at the same time may approach .each other, as forced by anyextra contraction of thc seat-bed.

. lhe valve-rod R is connected to the valve by suitable collar-plates,P, which are allowed to slide vertically upon the valve, and therebypermit the self-lining of the'valve-rod through the stuffing-box ofthestcam-chest. The valve is set upon the rod by the nuts p, in the usualmanner. The ports B both lead into one end of the cylinder, and B intothe other. rlhe exhaust-ports C both communicate inl one discharge-pipe.The wear caused by the gravity of the valve comes upon the plain surfaceof the bed A, and when it is running empty it moves loosely between theseats. Arigid crsolid double valve may be used, if desired, bysubstituting anew one occasionally, in case it should become worn atall, so as to be leaky.

We (lo not claim slide-valves having two parallel seats and adjustablefaces, as shown in the patent of David Pyke, April 2. 1867, but .i i f iWhat we do claim as our invention, and desire to secure by LettersPatent, is

he combination ofthe fixed nutig, screw-head It, with the double-seatedvalves E and F, whereby thc seats of the valves are'allowed to workfreely, irrespective of expansion and contraction of the steam-chest,substanlinlly upon the principle as herein set forth. v

JEROME STCCKING,

EDWARD I. SHAFFER.

Witnesses z i WM. S. LoUGHBoRoUon,

JAMES (l. CAMresm..

